console help

[nutonestudios]

hi there,
i have a tascam m-700 console and it has a number of channels that intermittently crackle and and the audio cuts out. if i open up the gain pot all the way, the audio comes back but will eventually cut out again. some of these had bad solder joints on the gain pots and i fixed this but some are still doing it. any ideas what this could be? opamps maybe?
thanks so much

 

[idylldon]

[quote author="nutonestudios"]hi there,
i have a tascam m-700 console and it has a number of channels that intermittently crackle and and the audio cuts out. if i open up the gain pot all the way, the audio comes back but will eventually cut out again. some of these had bad solder joints on the gain pots and i fixed this but some are still doing it. any ideas what this could be? opamps maybe?
thanks so much[/quote]

Sounds like more bad solder joints/connections somewhere in the signal path or, if the ICs are socketed, perhaps some oxidation on the IC pin/socket connection. Have you tried removing and then reseating the ICs?

One channel of my Neotek did this occasionally and I traced it down to a *bent* pin on one of the ICs. When someone pushed it in, one of the pins folded back and didn't enter the socket; however, there was still just enough of a connection to work intermittently.

Cheers,
--
Don

 

[nutonestudios]

thanks for the reply don. i have checked all the solder joints and they seem ok (although that has been a major problem in this console). the opamps. unfortunately, are board mounted, so no sockets. i've checked all the jumpers, etc, and all the connections seem to be fine... this is driving me nuts!

 

[Svart]

look at your insert and input/output jacks. if they are slightly corroded they will also do this.

 

[nutonestudios]

yeah, i had that problem with the inserts on a amek console i had, but this console has switches to engage the inserts and the problem happens regardles if they are "in" or "out"

 

[bcarso]

Agree with the others that it is almost certainly a flaky contact problem somewhere.

Can you get access to the sections enough to tap on various parts with a little non-conductive stick of some sort?

Are those switches you spoke of in the circuit(s) in either the normally open or normally closed position all the time? Switches are notorious for becoming intermittent unless they have large amounts of wiping action when actuated (miniature toggles decidedly do not, for example).

 

[nutonestudios]

im afraid it would be nearly impossible to get anything in for tapping while the module is in the console... the insert switches are normally "out when in the up position. that is, you have to depress the switch to engage the insert. also, something to add, the channel meters are unaffected when the channel cuts out...